The present invention relates generally to printing presses and more specifically to web offset printing presses having separable blankets.
U.S. Pat. No. 4,240,346 describes for example a printing press with two blanket cylinders separable from each other to permit a blanket throw off. In such presses, the blankets are offset from a vertical from each other, and in order to pass the web through the blankets when the blankets are offset, lead rolls or air bars are necessary to properly guide the web through the blankets. These guides can mark the printed product and also alter registration of the web between two printing print units, causing deteriorated print quality.
U.S. Pat. No. 6,343,547 describes a device to counterpoise a cylinder and a method for counterpoising a cylinder to be cantilevered on a printing press. U.S. Pat. No. 6,877,424 describes a counterpoise device for cantilevering at least one cylinder of a printing press having a movable counterpoise element for selectively contacting the cylinder and a stationary mount.
U.S. Pat. Nos. 6,216,592 and 6,019,039 describe printing units with throw-off mechanisms and are hereby incorporated by reference herein.